This application proposes several tests of a generalizable method for the coordinated handling of physiological and behavioral data. Such integrated analysis is needed to resolve ambiguities which have emerged in the isolated consideration of physiological and behavioral data which has typified fear research. Specifically, the proposal seeks to develop a reliable method of physiologically indicating fear by applying techniques of spectral and discriminant analysis which have proved fruitful in other disciplines. These techniques will locate periods of physiologically indicated fear which can then be incorporated into established analyses which have used similarly defined periods of fear and non-fear in prior behavioral studies. Multiple checks of the validity of the application of these physiological analysis techniques to dental fear are proposed using heart rate data previously collected from fearful dental patients. Moreover, after testing the new methodology, the analyzed, physiological data will be merged with related, existing, processed, behavioral data to form the desired coordinated data set. This integrated set will then be used to test two hypotheses. The first examines the efficacy of nitrous oxide sedation in reducing fear; the second provides a test of Lang's (1983) theoretical account of fear.